Interpretive Summary: Aflatoxins are toxic and carcinogenic secondary metabolites produced mainly by Aspergillus flavus and Aspergillus parasiticus that contaminate preharvest crops and post harvest grains. Scientists worldwide have extensively studied biosynthesis of aflatoxins for more than 50 years. Aflatoxin biosynthesis is a complex process involving many intermediates and enzymes. Regulation of aflatoxin gene expression occurs at multiple levels and by multiple regulatory components. There are genetic factors, biotic and abiotic elements that affect aflatoxin formation. Recent studies have shed more light on the functions of the enzymes involved in each of the steps of aflatoxin biosynthesis, the genes encoding those enzymes, and the regulatory mechanisms of aflatoxin formation. Better understanding of the mechanisms of aflatoxin biosynthesis helps to identify natural inhibitors of fungal growth aflatoxin formation, and eventually will allow design of effective strategies to can reduce or eliminate aflatoxin contamination of food and feed commodities.

Technical Abstract:
Aspergillus flavus is the most economically important because it produces the toxic and carcinogenic aflatoxins. A. flavus fungus is capable of surviving on many organic nutrient sources and is one of the most abundant soil-borne molds on earth. Aflatoxins were first identified in 1960. Over the last fifty years, the identification, characterization and toxic effects of aflatoxins have been extensive studied. During the last 20 years, the genes and enzymes, and genetic regulation of aflatoxin production have been reported. In this report, we summarized the progress of genetic and genomic research on the mechanism of aflatoxin formation and future research direction.